Invasive crayfish may pose new threat to Calgary-area trout

Wading out into the Elbow River, Trout Unlimited biologist Lesley Peterson is on the hunt for an invader entering new territory.

“Usually crayfish kind of hide under rocks,” Peterson said.

She was searching for them after a Calgarian snapped a photo of a crayfish in the Elbow on Tuesday, July 17.

Native to northern Alberta, they’re considering an invasive species in the Calgary area.

Crayfish have been spotted in Nose Creek and the Bow River since 2011 but until now, there hasn’t been a search for them in the Elbow.

“Unfortunately, they’re in the area and once they’re here, they tend to start moving around, either on their own or by people,” Peterson said.

Crayfish can pose a threat to native wildlife, eating small fish that trout feed on and also eating trout eggs.

The potential that they’re now spreading in the Calgary area also concerns veteran trout fishing guide Joe Buck.

“Crayfish, being as invasive as they are, it may affect the trout population,” Buck said. “So we’ve really got to protect it because it’s a Canadian treasure.”

Peterson’s search turned up no crayfish but the hunt for them will continue, which she says is not always a pleasant task.

“Sometimes when you’re lifting the rocks up, you can actually feel them crawl around your hands, which is kind of creepy.”